This is a puzzle whose variations many people would have done already. Yet, I found this to be very nice and not as simple as it may seem at first sight. I picked this from a Martin Garder book again “More Mathematical Puzzles and Diversions”. This specific puzzle is attributable to Henry Ernest Dudley, regarded as one of England’s greatest inventor of puzzles. This particular puzzle first appeared in a newspaper in 1903.

Look at the figure below. The spider is at the middle of an end wall, one foot from the ceiling and . The fly is at the middle of the opposite end wall, one foot above the floor and too paralysed with fear to move. What is the shortest distance the spider must crawl in order to reach the fly?

Figure: Puzzle 121

As always, please send your answers as comments within the blog (preferred), or send an e-mail to alokgoyal_2001@yahoo.com. Please do share the puzzle with others if you like, and please also send puzzles that you have come across that you think I can share in this blog.

Happy crawling and a Happy Diwali!